An FFT based algorithm for particle charge measurement in the presence of a square-wave excitation field using Phase Doppler Anemometry

This paper evaluates the performance of a bespoke signal processing algorithm based on spectral analysis to obtain aerosol particle charge distribution. The measurement method is based on tracking particle motion in square-wave excitation electric field using Phase Doppler Anemometry (PDA). The system performance has been tested using Monte Carlo simulations obtained from the synthesized Doppler burst signals. The velocity estimation range of the system was from 10 mm/s to 800 mm/s for a wide range of SNRs, with an error less than 1% for the velocity greater than 50 mm/s. The corresponding charge-mass ratio measurement range was from around 1 mu C/g to the saturation level. The percentage of successfully processed single and multi-burst signals was evaluated using numerical simulations.